[Atrial flutter and fibrillation]

This article summarizes current understandings and therapies for both arrhythmias. Atrial flutter is most often arising from a macroreentry circuit in the right atrium or around scar tissue in case or previous cardiothoracic surgery. As a macroreentrant tachycardia it is regular and can lead to higher heart rates, especially if occurring with 1:1 conduction. In contrast atrial fibrillation, especially when occurring paroxysmal at the beginning, is arising from triggers within the pulmonary veins. Ablation strategies to electrically isolate those triggers have a treatment success rate of 80%, which is much more than can be achieved with antiarrhythmic medication (success rates 30-50%). Emergency treatment of both arrhythmias include cardioversion and pacemaker implantation with AV node ablation if necessary.